Device for excluding water from a working site located adjacent to a body of water

ABSTRACT

A ship building dock has an opening defined by a threshold and two side posts, which is closed by a door structure including a vertical waist portion forming the closure proper and a lower balancing portion, which may be vertical or horizontal. The structure is designed in such a manner that the external water pressure upon the two portions will about balance each other, and the forces of reaction will appear about at the level of the threshold.

United States Patent [1 1 Ludvigsson Dec. 16, 1975 1 DEVICE FOREXCLUDING WATER FROM A WORKING SITE LOCATED ADJACENT TO A BODY OF WATER[76] Inventor: Birger Ludvigsson, Sodra vagen 38,

Goteborg, Sweden, 41234 [22] Filed: July 23, 1974 21 Appl. No.: 490,942

[30] Foreign Application Priority Data July 26, 1973 Sweden 7310358 [52]U.S. Cl. 61/64; 61/22 [51] Int. Cl. B63C l/08 [58] Field of Search61/64, 25, 22, 65, 8

[56] References Cited UNITED STATES PATENTS 3,133,420 5/1964 Burnett61/64 Noguchi 61/64 Solinas 61/64 X Primary Examiner-Jacob ShapiroAttorney, Agent, or Firmllolman & Stern [5 7 ABSTRACT A ship buildingclock has an opening defined by a threshold and two side posts, which isclosed by a door structure including a vertical waist portion formingthe closure proper and a lower balancing portion, which may be verticalor horizontal. The structure is designed in such a manner that theexternal water pressure upon the two portions will about balance eachother, and the forces of reaction will appear about at the level of thethreshold.

9 Claims, 5 Drawing Figures US. Patent Dec. 16, 1975 Sheet 2 of33,926,002

FIG

U.S. Patfint Dec. 16, 1975 Sheet 3 of 3 3,926,002

FIGS

DEVICE FOR EXCLUDING WATER FROM A WORKING SITE LOCATED ADJACENT TO ABODY OF WATER BACKGROUND OF THE INVENTION The present invention relatesto a device adapted to exclude water from a working site located belowthe water level. A ship building or repair dock is, usually at one ofits ends (sometimes at both ends), provided with a door structure whichalong its bottom and sides seats against the fixed structure of thedock. When the water is pumped out of the clock, the door structure willhave to take care of the hydrostatic pressure of the water outside thedock and to transfer this pressure to the bottom and the side walls ofthe clock, The static constructional system of the door structure isusually arranged in such a manner that a major portion of the waterpressure is transferred by way of one or more horizontal girders,resting against the dock walls. The girder system is often integratedinto a system of pontoons giving the necessary displacement for floatingthe door structure.

With the width of a door structure actual for todays docks such asupport structure for taking care of the water pressure will be veryuneconomical.

SUMMARY OF THE INVENTION The object of the present invention is toprovide a device including a door structure, which is lighter and thuseasier to handle and more economical than the traditional structure. Thebasic principle of the static system of a door structure according tothe invention implies that the primary carrying system acts as a bracketwhich is supported at the level of the bottom of the entrance opening(the threshold thereof).

A device according to the invention may be used for excluding water fromany working site located adjacent to a body of water and being separatedtherefrom by a wall having an opening defined by a threshold and twoside posts, the device including a door structure operable in anysuitable manner. The invention is characterized in that the portion ofthe door structure adapted, in mounted position, to take care of thesidewardly directed, uni-lateral water pressure is designed in such amanner that the forces of reaction substantially will appear at itslower part, to be transferred by way of the threshold, with the doorstructure further being designed in such a manner that the waterpressure will force it against the treshold.

BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1, 2, 3 and 5 show various typesof door structures, with the views being cross sections through theopening end of a ships dock and FIG. 4 is a top partial view of FIG. 3.

DESCRIPTION OF SOME PREFERRED EMBODIMENTS FIG. 1 shows a portion of adock adjacent to the opening giving access to the sea. The bottom of thedock is terminated by a threshold structure generally denoted by 11, andextending somewhat outside the side walls of the dock. Vertical endportions 12 of these walls will, together with the threshold, define theopening to the dock, and it should be remembered that the width of suchan opening is considerably larger than the depth of the water.

2 A cross section through the door structure resembles an inverted T. Awaist portion thereof, or a door panel proper 13, is rigidly connectedto a flange portion or sole 14. The threshold 11 is provided with aninner 5 transom 17 against which the sole 14 rests at 19, and

which prevents a displacement inwards of the door structure. Thehorizontal portion of the threshold is arranged in such a manner that anenclosed zone will be defined between the threshold and the lower faceof the sole 14. As shown, this zone preferably is formed as a recess 15,extending along a substantial part of the sole, and which, in a simplearrangement, communicates with the clock by way of a passage 16. Thewater pressure within the recess 15 will, in other words, depend uponthe water level within the dock.

When the dock is evacuated, the water outside the dock will exert alaterally directed pressure upon the door structure.

The main horizontal component of this pressure will be taken care of bythe contact between the sole and the threshold. The tilting moment uponthe door structure is balanced by the load of the water externallyapplied to the sole being greater than the upwardly directed pressure inthe recess 15, which pressure is determined by the water level withinthe dock.

Sealing means 18 and 20 are arranged between the door panel 13 and theside posts 12, as well as between the sole 14 and portion 21 of the solesurrounding the recess and defining the same against the surroundingwater. The main components of the static system of the door structureare to be found in, and adjacent to the sole and by the balancing forcesexerted by the water, a very light structure is obtained, also when thedoor is considerably wide. The weight of the structure, as calculatedper meter thereof, will be independent of the width of the opening.

The threshold may be substantially plane, on which occasion the zone tobe evacuated will be defined by the sealing means. A recess maypossibly, wholly or partly, be located in the lower face of the sole.

According to a development of the invention, further sealing means 22may also be fitted between the threshold and the sole in order to sealoff completely the recess 15 towards the dock as well as towards thewater outside the same. The passage 16 will then be led elsewhere thanto the dock and will be connected to a pump. By removing water from therecess 15, a lower pressure will be obtained therein, which increasesthe stability of the door structure. In order to prevent entrance of airinto the recess 15, the sealing means 22 should be located in such amanner that they are always covered by water.

With the embodiment according to FIG. 2, the threshold and the doorstructure are designed in a somewhat different manner.

A door structure 23 is here fonned as a substantially flat panel havingan enlarged cross section at the portion intended to rest at an upperedge 24 of the threshold and including the main structural element ofthe door supporting system. The threshold is provided with alongitudinally running channel 25, extending all along the opening andbeing designed with a satisfactory clearance to receive a lower portion26 of the door panel 23. V

The recess 15 is here formed in the inward wall defining the channel,and in the same manner as previously described, sealing means 18 areprovided between the door structure and the side posts 12. Furthersealing 3 means 20 are fitted between the threshold and the doorstructure and still further sealing means 22 around the recess 15. Thelatter may be evacuated by way of passage 16.

The pressure of the water upon the portion 26 of the lower doorstructure extending down into the channel is greater than the pressureacting upon the upper portion of the structure, whereby a balancing ofthe forces acting upon the panel is obtained and thus favorableconditions for a light weight structure.

The door structure may be locked with respect to the threshold bysuitable means. Such means may, with the embodiment according to FIG. 1,include devices 27, adapted to pull the outwardly turned edge of thesole downwards, and with the embodiment according to FIG. 2, of rams 28forcing the lower edge of the door panel against the inner wall of thechannel. These means will thus aid in balancing the pressure upon theupper portion of the door panel.

FIGS. 3 and 4 show a further embodiment, which may be regarded as asimplification of that shown in FIG. 1.

The door structure has a basically L-shaped cross section, with avertical waist 30, forming the closure proper and a lower, horizontalsole 31. These will together provide a single walled shell structure,the base part of which is carried by strong beams 32, and is supportedtherefrom by means of stays and struts 33.

The upper part of the door structure is formed as a travelling track 34,providing a passageway between the side walls 12 of the dock 10.

The door structure rests, when fitted in position, upon a thresholdincluding an outer transom 35 and an inner row of spaced projections 36.Between the transom 35 and the row of projections 36 the zone to beemptied is formed as a trench. The projections 36 will permit water fromthe dock to flow into the trench, and the dock will thus be emptied byway of the connection 16.

The horizontal sole 31 and the beams 32 supporting the same are providedwith downwardly directed arms 37, which engage the transom 35 and willtake care of the horizontal forces acting upon the door structure.Sealing means are provided between the arms and the sill.

A floating tank 39 is fitted at each end of the door structure and means(not shown) will make it possible to fill or to empty said tanks,respectively, in order to make the door structure non-displacing ordisplacing, as is desirable in order to maintain the door structure inposition, or make it floating for towing.

Further sealing means 18 are, as with the earlier embodiments, providedalong the vertical edges of the door structure.

The door structures shown may be formed as a single unit extending allacross the opening, but may also be subdivided into sections. In thelast mentioned situation sealing means will have to be provided betweenthe sections.

The door structure, or the sections thereof, are operated in anysuitable manner when the clock has been filled with water, for instance,through floating by means of pontoons, which are permanently built intothe structure, as described in connection with FIGS. 3 and 4, or aretemporarily attached thereto. Due to its light weight structure, thedoor, especially the one shown in FIG. 2, may be operated by means ofsuch cranes as are usually available in conjunction with a ship buildingdock.

FIG. 5 shows a devlopment of the door structure disclosed in FIG. 2. Thesame reference numerals are used for the main components.

The door structure includes a number of separate buoyancy tanks 40, witheach communicating with the surrounding water by at least one opening 41located in the lower end of the pertaining tank. Each tank further isconnected to a pipe 42 for supplying compressed air.

This is supplied through a hose 43 to a distribution box 44. Valves 45will govern the supply of air to the individual tanks 40 to drive thewater therein out through openings 41, thereby determining the buoyancyof the door structure.

The lowermost tank may be filled with ballast, and the topmost one maybe open towards the sea. In closing position, a sufficient number of thetanks 40 in the door structure are filled with water, so the door has notendency to lift from the threshold.

When it is desirable to open the dock some, more tanks are filled withwater, whereupon the door structure sinks down to a horizontal positionoutside the dock, as is indicated in the dashed lines. The threshold isdesigned in such a manner that the lower margin of the door structureremains within the recess 15. The sinking movement may be guided bysuitable means (not shown), such as cables from capstans or cranesnormally provided at the dock.

It is also possible first to increase the buoyancy of the doorstructure, so the same first rises vertically out of engagement with thethreshold, and is then towed outside the same to be sunk to a horizontalposition outside the same, as above described,

For raising the door structure, air is reintroduced into the tanks 40 inproper order, whereby water is expelled and the door structure isbrought back to its vertical position.

This design is particularly suitable with repair docks, as a very rapidfitting and removal of the door structure is possible.

What I claim is:

1. A device for use in excluding water from a working site locatedadjacent a body of water and beneath the water level thereof in which awall separates the working site from the body of water, with the wallhaving an opening providing communication between the working site andthe body of water, a threshold and two side posts constituting saidopening, the threshold including portions located inwardly and outwardlyof the wall, the device comprising a door structure closing the opening,the door structure including a vertical waist portion defining theclosure proper and a lower balancing portion rigidly connected to thewaist portion, the lower balancing portion cooperating with at least oneof said portions of the threshold to provide a zone communicating withthe working site and the water pressure in the zone being dependent uponthe water level within the working site, and means cooperable with thelower balancing portion and the threshold to prevent inward movements ofthe door structure in a horizontal direction, the arrangement being suchthat upon evacuation of the working site, the water outside the workingsite will exert a laterally directed pressure upon the door structurewith the main horizontal component of such pressure being taken care ofby the cooperation between the lower balancing portion of the doorstructure and said at least one portion of the threshold and the tiltingmoment upon the door structure being balanced by the load of the waterexternally applied to the lower balancing portion being greater than theupwardly directed pressure in the zone which is dependent on the waterlevel within the working site.

2. The device as claimed in claim l in which said zone is a recess.

3. The device as claimed in claim 1 in which said lower balancingportion of said door structure is defined by a horizontal sole which issupported by said portions of the threshold located inwardly andoutwardly of the wall.

4. The device as claimed in claim 3 in which the outwardly locatedportion of the threshold is provided with an upwardly directed transomand the sole is provided with downwardly directed arms for cooperationwith the transom, the transom and arms constituting the means to preventinward movements of the door structure in a horizontal direction.

5. The device as claimed in claim 3 in which the sole is provided withan inwardly directed extension and the inwardly located portion of thethreshold is provided with an upwardly directed transom, the extensionand transom constituting the means to prevent inward 6 movements of thedoor structure in a horizontal direction.

6. The device as claimed in claim 1 in which the threshold is providedwith a longitudinally extending channel for receiving the lowerbalancing portion of the door structure.

7. The device as claimed in claim 6 in which the door structure isprovided with buoyancy tanks, and means operably connected to the tanksfor adjusting their carrying capacity, with said means being operable tolower the door structure onto the water bed outside of the wallseparating the working site from the body of water.

8. The device as claimed in claim 1 including locking means provided atthe threshold for aiding in counteracting the tilting movement upon thedoor structure caused by the unilateral pressure of the water,

9. The device as claimed in claim 1 in which the zone, at leastoutwardly with respect to the threshold is provided by sealing memberscovered by water even when the working site is dry, and means connectedto the zone for removing water therefrom.

1. A device for use in excluding water from a working site locatedadjacent a body of water and beneath the water level thereof in which awall separates the working site from the body of water, with the wallhaving an opening providing communication between the working site andthe body of water, a threshold and two side posts constituting saidopening, the threshold including portions located inwardly and outwardlyof the wall, the device comprising a door structure closing the opening,the door structure including a vertical waist portion defining theclosure proper and a lower balancing portion rigidly connected to thewaist portion, the lower balancing portion cooperating with at least oneof said portions of the threshold to provide a zone communicating withthe working site and the water pressure in the zone being dependent uponthe water level within the working site, and means cooperable with thelower balancing portion and the threshold to prevent inward movements ofthe door structure in a horizontal direction, the arrangement being suchthat upon evacuation of the working site, the water outside the workingsite will exert a laterally directed pressure upon the door structurewith the main horizontal component of such pressure being taken care ofby the cooperation between the lower balancing portion of the doorstructure and said at least one portion of the threshold and the tiltingmoment upon the door structure being balanced by the load of the waterexternally applied to the lower balancing portion being greater than theupwardly directed pressure in the zone which is dependent on the waterlevel within the working site.
 2. The device as claimed in claim 1 inwhich said zone is a recess.
 3. The device as claimed in claim 1 inwhich said lower balancing portion of said door structure is defined bya horizontal sole which is supported by said portions of the thresholdlocated inwardly and outwardly of the wall.
 4. The device as claimed inclaim 3 in which the outwardly located portion of the threshold isprovided with an upwardly directed transom and the sole is provided withdownwardly directed arms for cooperation with the transom, the transomand arms constituting the means to prevent inward movements of the doorstructure in a horizontal direction.
 5. The device as claimed in claim 3in which the sole is provided with an inwardly directed extension andthe inwardly located portion of the threshold is provided with anupwardly directed transom, the extension and transom constituting themeans to prevent inward movements of the door structure in a horizontaldirection.
 6. The device as claimed in claim 1 in which the threshold isprovided with a longitudinally extending channel for receiving the lowerbalancing portion of the door structure.
 7. The device as claimed inclaim 6 in which the door structure is provided with buoyancy tanks, andmeans operably connected to the tanks for adjusting their carryingcapacity, with said means being operable to lower the door structureonto the water bed outside of the wall separating the working site fromthe body of water.
 8. The device as claimed in claim 1 including lockingmeans provided at the threshold for aiding in counteracting the tiltingmovement upon the door Structure caused by the unilateral pressure ofthe water.
 9. The device as claimed in claim 1 in which the zone, atleast outwardly with respect to the threshold is provided by sealingmembers covered by water even when the working site is dry, and meansconnected to the zone for removing water therefrom.